Why I can't get blackboard？

[HEparen (HaiFan Zhou)]

I write an easy scripting,but it doesn’t work.It always tell me the value of Get Blackboard is not vaild.I don’t know how to solve this problem.

and this is my AIController [alt text][2]

[Kehel18]

Hello! Use this to init Blackboard Use Blackboard | Unreal Engine Documentation